Interlacing boot for two-row ferrule ribbon for one dimensional photonic chip beach front

ABSTRACT

Embodiments of the present invention are directed to an interlacing boot and methods of using the same to automatically interleave optical fibers in a two-row array, such from a two rows ferrule. In a non-limiting embodiment of the invention, the optical fibers are inserted into a first end of an interlacing boot in a first direction. The interlacing boot can include a guiding structure having one or more channels. Each channel can be adapted to receive a single optical fiber. Each channel can include a first end and a second end, and the second end can be offset with respect to the first end in a second direction orthogonal to the first direction. The interlacing boot can be pushed towards the ferrule to feed the optical fibers through the guiding structure. The first row of fibers can be physically offset from and interlaced with the second row of fibers by the guiding structure.

This application is a continuation of U.S. patent application Ser. No.16/654,272, filed Oct. 19, 2019, the disclosure of which is incorporatedby reference herein in its entirety.

BACKGROUND

The present invention relates generally to ribbons and multi-termination(MT) ferrule use in optical fiber connectors. More specifically, thepresent invention relates to an interlacing boot for a two-row fiberarray from a ferrule for a one dimensional (1D) photonic chip beachfront.

Fiber optic arrays or fiber optics ribbons (sometimes referred to hereinsimply as “ribbons” for convenience) are supplied with severalindividual optical fibers disposed parallel to one another. Eachindividual optical fiber includes a glass core and a glass cladding,both of which are protected in a polymeric coating, which can be colorcoded. A plurality of these individual optical fibers are impregnated ina polymeric ribbon matrix to form a fiber optic ribbon. Fiber opticribbons are typically supplied as 2-fiber ribbons, 4-fiber ribbons,8-fiber ribbons, 12-fiber ribbons and 16-fiber ribbons. An array ofoptical fibers can include multiple optical fibers placed parallel toeach other, and can include fibers of various types, order, and mix.

Optical fiber connectors typically use a ferrule in which the opticalfibers are terminated and secured. The multiple termination (MT) ferruleis one such ferrule commonly used in optical fiber applications where afiber optic ribbon or optical fiber array are terminated into theferrule connector. The MT ferrule is ubiquitous because it canaccommodate a variety of different numbers of optical fibers and fiberoptic ribbons. For example, an MT 24 ferrule can accommodate up to 24optical fibers, while an MT 8 ferrule serves just eight fibers. Usually,the optical fibers are stacked in an array of one, two, or four rowsand, as example in the case of an MT 24 ferrule, we have a layout of tworows of 12 fibers or equivalently twelve columns of two fibers.

SUMMARY

Embodiments of the invention are directed to an interlacing boot foroptical fibers. A non-limiting example of the interlacing boot includesa body having a first end adapted for insertion over a ferrule withmultiple rows of fibers arrays and a second end opposite the first end.The second end includes an opening. The body is tapered between thefirst end and the second end in a first direction. The interlacing bootfurther includes guiding structures disposed within the body. Theguiding structures include one or more channels and each channel isadapted to receive a single optical fiber. Each channel includes a firstend and a second end, and the second end is offset with respect to thefirst end in a second direction orthogonal to the first direction.

Embodiments of the invention are directed to a method for using aninterlacing boot to automatically interleave optical fibers from atwo-row fiber array. A non-limiting example of the method includesinserting the optical fibers into a first end of an interlacing boot ina first direction. The interlacing boot can include guiding structureshaving one or more channels. Each channel can be adapted to receive asingle optical fiber. Each channel can include a first end and a secondend, and the second end can be offset with respect to the first end in asecond direction orthogonal to the first direction. The interlacing bootcan be pushed along the arrays, or towards a multiple row ferrule, tofeed the optical fibers through the guiding structure. The first row offibers can be physically offset from and interlaced with the second rowof fibers by the guiding structure.

Embodiments of the invention are directed to a method for using aninterlacing boot to automatically interleave optical fibers frommultiple ribbons. A non-limiting example of the method includes feedingthe optical fibers into an interlacing comb in a first direction. Theoptical fibers include a first row of fibers and a second row of fibers.The interlacing comb includes a guiding structure having one or morechannels. Each channel is adapted to receive a single optical fiber.Each channel includes a first end and a second end, and the second endis offset with respect to the first end in a second direction orthogonalto the first direction. The method includes moving the optical fibersthrough the interlacing comb to force the optical fibers through theguiding structure. The first row of fibers are physically offset fromand interlaced with the second row of fibers by the guiding structure.The method includes inserting the optical fibers into a first end of aninterlacing boot and removing the interlacing comb.

Additional technical features and benefits are realized through thetechniques of the present invention. Embodiments and aspects of theinvention are described in detail herein and are considered a part ofthe claimed subject matter. For a better understanding, refer to thedetailed description and to the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The specifics of the exclusive rights described herein are particularlypointed out and distinctly claimed in the claims at the conclusion ofthe specification. The foregoing and other features and advantages ofthe embodiments of the invention are apparent from the followingdetailed description taken in conjunction with the accompanying drawingsin which:

FIG. 1 depicts an isometric view of a two-row ferrule before and afterinsertion into an interlacing boot in accordance to one or moreembodiments of the invention;

FIG. 2A depicts a top-down view of the two-row ferrule and theinterlacing boot shown in FIG. 1 according to one or more embodiments ofthe invention;

FIG. 2B depicts a cross-sectional view of the two-row ferrule and theinterlacing boot shown in FIG. 1 according to one or more embodiments ofthe invention;

FIG. 3A depicts a top-down view of the two-row ferrule and theinterlacing boot shown in FIG. 1 after the optical fibers have beenguided partially through the interlacing boot according to one or moreembodiments of the invention;

FIG. 3B depicts a cross-sectional view of the two-row ferrule and theinterlacing boot shown in FIG. 1 after the optical fibers have beenguided partially through the interlacing boot according to one or moreembodiments of the invention;

FIG. 4A depicts a top-down view of the two-row ferrule and theinterlacing boot shown in FIG. 1 after the optical fibers have beenguided through a first portion of the interlacing boot according to oneor more embodiments of the invention;

FIG. 4B depicts a cross-sectional view of the two-row ferrule and theinterlacing boot shown in FIG. 1 after the optical fibers have beenguided through a first portion of the interlacing boot according to oneor more embodiments of the invention;

FIG. 5A depicts a top-down view of the two-row ferrule and theinterlacing boot shown in FIG. 1 after the optical fibers have beenguided through the interlacing boot according to one or more embodimentsof the invention;

FIG. 5B depicts a cross-sectional view of the two-row ferrule and theinterlacing boot shown in FIG. 1 after the optical fibers have beenguided through the interlacing boot according to one or more embodimentsof the invention;

FIG. 6A depicts a top-down view of the two-row ferrule and theinterlacing boot shown in FIG. 1 after the interlacing boot has beenpushed over the fiber optic ribbons to the base of the two-row ferruleaccording to one or more embodiments of the invention;

FIG. 6B depicts a cross-sectional view of the two-row ferrule and theinterlacing boot shown in FIG. 1 after the interlacing boot has beenpushed over the fiber optic ribbons to the base of the two-row ferruleaccording to one or more embodiments of the invention;

FIG. 7 depicts a cross-sectional view of a two-row ferrule beinginserted into a temporary interlacing comb according to one or moreembodiments of the invention;

FIG. 8 depicts a flow diagram illustrating a method according to one ormore embodiments of the invention; and

FIG. 9 depicts a flow diagram illustrating a method according to one ormore embodiments of the invention.

The diagrams depicted herein are illustrative. There can be manyvariations to the diagram or the operations described therein withoutdeparting from the spirit of the invention. For instance, the actionscan be performed in a differing order or actions can be added, deletedor modified.

In the accompanying figures and following detailed description of thedescribed embodiments of the invention, the various elements illustratedin the figures are provided with two or three-digit reference numbers.With minor exceptions, the leftmost digit(s) of each reference numbercorrespond to the figure in which its element is first illustrated.

DETAILED DESCRIPTION

It is understood in advance that although example embodiments of theinvention are described in connection with a particular ferrulearchitecture example (e.g., a 2×12 ribbon to 24-fiber ferrule),embodiments of the invention are not limited to the particular ferrulearchitectures described in this specification. Rather, embodiments ofthe present invention are capable of being implemented in conjunctionwith any ribbon configuration (2-row, 3-row, N-row, etc.) having anyarbitrary number of optical fibers (an even or odd number of fibers, alarge number of fibers, few fibers, various mixes of fiber types such ashigh-NA or PM maintaining fibers, etc.).

Turning now to an overview of technologies that are more specificallyrelevant to aspects of the present invention, fiber optic connectors arebeing designed to handle higher numbers of optical fibers to provide fora larger number of optical communication channels. For example, while itis very common to have a fiber optic connector terminated with two,eight, or 12 individual optical fibers, but in some applications, it ismore desirable to terminate a similar connector with 24, 32, 48, or evenmore optical fibers.

As used herein an “individual optical fiber” is one that has a glasscore surrounded by a glass cladding, which is surrounded by a polymericcoating. That is, an individual optical fiber differs from a fiber opticribbon in that the former does not contain any polymeric matrix to holdthe single optical fibers together. As used herein, the term “exposedoptical fibers” means that the polymeric matrix and the polymericcoating has been removed from the ribbon, thereby exposing the glasscladding.

Optical fiber connectors typically use a ferrule in which the individualfibers in a fiber optic ribbon or ribbons are terminated and secured.When multiple fiber optic ribbons and their associated individual fibersare manually installed into a ferrule, the process can be very timeconsuming in part due to the relatively small and rather delicate natureof the fiber optic ribbon. Manual installation is particularly difficultgiven the small dimensions involved, such as a typical 8-fiber ribbonbeing only about 2 mm wide and 0.32 mm thick, with each individualcoated optical fiber therein being only 250 micrometers in diameter.This is even more true in applications that require axis alignments,such as when a PM fiber rotational alignment of the transverse axis isrequired to clock the PM inside the ferrule.

Some common practices for installing multiple ribbons into a ferrule,such as a guiding ferrule, is to install one ribbon at a time using av-groove or ribbonization tool. The 24-fiber, multiple ribbon MT 24ferrule, for example, has been designed with stepped rows of v-groovesinside the ferrule, each v-groove row functioning to guide and toaccommodate a ribbon. As used herein, a “v-groove” refers to a groovehaving a generally v-shaped cross-sectional profile (sometimes referredto as teeth), typically positioned adjacent to an MT ferrule to increasefiber density. Usually, one installs the bottommost ribbon first, wherethe v-grooves are the longest, by aligning the fibers of the ribbonwithin the channel defined by the guiding v-grooves and then pushing thefibers into the connected fiber holes. One then installs a second ribbonin a second row of v-grooves that is slightly shorter than the firstrow. Because most ferrules have an opening on the top, an installer canvisually watch the ribbons entering each row of v-grooves. Whilev-grooves allow for multiple ribbons to be installed into a singleferrule, interlacing is difficult and typically done manually. Duringinstallation, fibers are placed one by one at the proper location (orribbon by ribbon, where ribbon lateral offset requires large distancefor the bend). Such a process can be very time consuming and can producea low yield.

Ribbonization tools, whereby multiple input fibers are recombined intoribbons, also struggle with interlacing, especially at high fiberdensities. When using a ribbonization tool, multiple fibers are inserted(from an MT or fanout bloc, for example) one by one into predeterminedlocations in the ribbonization tool. Once the interlacing is manuallyassured, the ribbonization tool can be used to realign stacked fibersinto a 1D configuration.

Consequently, while both v-grooves and ribbonization tools canultimately provide 1D fiber configurations, neither approach iswell-suited to complete automation, as both require manual interventionand careful fiber review before or during fiber interlacing. It would behighly advantageous to provide a ferrule assembly that can automaticallyhandle arbitrary fiber density interlacing without introducing defectsor optical fiber misalignments.

Turning now to an overview of aspects of the present invention, one ormore embodiments of the invention address the above-describedshortcomings of the prior art by providing a new interlacing boot fortwo-row ferrule ribbons that automatically interlaces fibers duringinsertion. This new interlacing boot contains one or more guidingstructures that physically offset and interlace optical fibers as thosefibers are moved through channels in the guiding structures duringinsertion.

Unlike conventional v-grooves, which run parallel to each other straightin the direction of fiber insertion, the present guiding structures caninclude channels that are constructed with arbitrary offset angles withrespect to the path of insertion. As an optical fiber enters a channelin the guiding structure, the optical fiber will be guided through thechannel and physically deflected by the channel's offset angle. Thechannels can be constructed such that each fiber enters a differentchannel and each fiber achieves any desired level of offset at any pointalong the channel's length.

The interlacing boot itself and/or channels in the guiding structure canbe tapered such that each fiber is automatically and physicallyinterleaved after sufficient offsetting has been achieved (at a pointthat can also be arbitrarily defined and based, for example, on thestress level of the fiber and tolerable bending radii for the givenapplication). In short, an optical fiber enters a channel and is forcedinto an offset via the channel's path. The fiber is then forced into aninterleaved position with respect to other fibers by the tapering of theinterlacing boot (or by tapering of the guiding channels, or both). Asthis interlacing boot provides a mechanism to physically andautomatically offset and interlace optical fibers, it is well-suited tohigh fiber count applications, such as high fiber density single rowconnections needed in silicon photonics optical connections, while stillbeing compatible with standard off-the-shelves MT components. Moreover,the custom nature of the channels allows for arbitrary changes in finalfiber pitch. In some applications, the final fiber pitch can be largeror smaller than the initial pitch of either row of fibers. For example,when combining two rows of fibers the final pitch can be twice theoriginal pitch (e.g., interleaving a top row into a bottom row), or morethan twice the original pitch (e.g., interleaving both rows to reducepitch between adjacent fibers), or less than twice the original pitch(e.g., the channel offsetting can increase the pitch between adjacentinterleaved fibers).

Turning now to a more detailed description of aspects of the presentinvention, FIG. 1 depicts an isometric view of a two-row ferrule 100before (images above) and after (combined image below) insertion into aninterlacing boot 102 according to one or more embodiments of theinvention. As shown in FIG. 1, the two-row ferrule 100 includes twovertically stacked rows of optical fibers 104 (also referred to as a 2Darray of fibers). While shown as having eight total fibers in a 2×4configuration for ease of illustration, it is understood that thetwo-row ferrule 100 can include any number of vertically stacked opticalfibers, as in a special custom made multi-row ferrule, or in an MTmulti-row ferrule manufactured to industry standards. As an example, thetwo-row ferrule 100 can include 24 optical fibers arranged in a two-rowof 12 configuration.

During insertion into the interlacing boot 102, the optical fibers 104are physically offset via channels constructed within the body of theinterlacing boot 102 (see FIG. 2A). The optical fibers 104 aresubsequently and/or concurrently interleaved via tapering in thechannels or the body of the interlacing boot 102 (see FIG. 2B). Afterinsertion, the optical fibers 104 leave the interlacing boot 102 as asingle row of fibers (a 1D array of fibers) having twice the fiberdensity.

FIGS. 2A-6B depict the successive insertion of a two-row ferrule ribboninto an interlacing boot according to one or more embodiments of theinvention. FIG. 2A depicts a top-down view of the two-row ferrule 100and the interlacing boot 102 shown in FIG. 1. FIG. 2B depicts across-sectional view of the two-row ferrule 100 and the interlacing boot102 shown in FIG. 1.

As shown in FIG. 2A, the two-row ferrule 100 can include an array offiber optic ribbons 200. End portions of the fiber optic ribbons 200 canbe removed or stripped of polymeric material to expose an array ofsingle optical fibers 202. While not viewable in the top-down view shownin FIG. 2A (due to obstruction by the top row fibers), it can be easilyseen in FIG. 2B that the array of optical fibers 202 includes twovertically stacked rows of fibers.

As further shown in FIG. 2A, the optical fibers 202 can be inserted intoan opening in the interlacing boot 102. The interlacing boot 102 caninclude one or more channels 204 defined by a guiding structure 206. Insome embodiments of the invention, the channels 204 are constructed suchthat only a single fiber of the optical fibers 202 can fit within aparticular channel.

The channels 204 can be offset, either abruptly or gradually, from theaxis of insertion. As shown, the channels 204 are gradually offsetwithin a first portion “A” to a final degree of offsetting achievedwithin a second portion “B.” In other embodiments of the invention,offsetting occurs along the entire length of the channels (i.e., “B” issmall or nonexistent). While a single example of the portions “A” and“B” are shown for ease of illustration, it is understood that the lengthratio between “A” and “B” can be arbitrarily set to achieve a giventotal offset over any arbitrary distance, depending on the needs of agiven application.

In some embodiments of the invention, the guiding structure 206 isconstructed such that only fibers from a single row of the two-rowferrule 100 enter channels (as shown, only the top fibers enter achannel). In this manner, only one of the rows of fibers will be offsetwithin the channels (top or bottom rows, as desired). In otherembodiments, the guiding structure 206 is constructed such that bothrows of fibers enter channels (not shown for ease of illustration). Inthis manner, both rows of fibers are offset within the channels. In someembodiments of the invention, the top row is offset in a first directionwhile the bottom row is offset in a second direction. While increasingthe complexity of the interlacing boot 102, allowing for simultaneousoffsetting of both rows allows for the total offsetting distance to bereduced (halved if desired), and also enables a custom and specificfinal fiber pitch by offsetting the arrays accordingly.

As shown in FIG. 2B, the interlacing boot 102 can be tapered to forcethe optical fibers 202 into a single row (a 1D array). Tapering canoccur over the entirety (as shown) or over only a portion of theinterlacing boot 102. In some embodiments of the invention, theinterlacing boot 102 is constructed such that tapering occurs afteroffsetting (i.e., after the portion “A” shown in FIG. 2A). In someembodiments of the invention, the interlacing boot 102 is constructedsuch that tapering occurs after a portion, but not all, of theoffsetting has occurred (i.e., some distance within portion “A” shown inFIG. 2A). Where this tapering distance occurs can be adjusted to ensurethat sufficient offsetting of the fibers is achieved prior tointerlacing, and can be based, for example, on the vertical distancebetween the two rows of fibers as well as on the pitch between adjacentfibers.

FIG. 3A depicts a top-down view of the two-row ferrule 100 and theinterlacing boot 102 shown in FIG. 1 as the optical fibers 202 have beenguided along the channels 204 partially through the portion “A” of theinterlacing boot 102. FIG. 3B depicts a cross-sectional view of thetwo-row ferrule 100 and the interlacing boot 102 shown in FIG. 1 as theoptical fibers 202 have been guided along the channels 204 partiallythrough the portion “A” of the interlacing boot 102.

As shown in FIG. 3B, only the top row fibers enter the guiding structure206, resulting in a partial offset of the top row fibers (with respectto the bottom row fibers). As further shown in FIG. 3B, the bottom rowfibers enter the interlacing boot 102 and continue under the guidingstructure 206 (bypassing this structure) until hitting the taperedsidewall. In some embodiments of the invention, the bottom row fibers donot bypass the guiding structure 206, but instead enter a second portionof the guiding structure 206 (not shown). In this manner, both the topand bottom fibers can be offset and placed to a new interleaved outputpitch as discussed previously.

In some embodiments of the invention, tapering can occur after partialor complete offsetting of the fibers. As shown in FIGS. 3A and 3B, thetop row fibers have been partially offset by the time the fibers hit thetapered sidewall of the interlacing boot 102 (the “TAPER” sectiondepicted in FIG. 3B). It is understood, however, that tapering can occurbefore, at any point during, or after offsetting of the optical fibers202, by adjusting the sidewall construction of the interlacing boot 102.

FIG. 4A depicts a top-down view of the two-row ferrule 100 and theinterlacing boot 102 shown in FIG. 1 as the optical fibers 202 have beenguided along the channels 204 through the portion “A” and into theportion “B” of the interlacing boot 102. FIG. 4B depicts across-sectional view of the two-row ferrule 100 and the interlacing boot102 shown in FIG. 1 as the optical fibers 202 have been guided along thechannels 204 through the portion “A” and into the portion “B” of theinterlacing boot 102.

As shown in FIG. 4A, the interlacing boot 102 has been sufficientlyinserted over the optical fibers 202 such that the top row fibers havebeen fully offset from the bottom row fibers. In other words, theoptical fibers 202 have entered the portion “B” of the interlacing boot102. As shown in FIG. 4B, the optical fibers 202 have hit the taperedsidewall of the interlacing boot 102. As a result, the optical fibers202 have been forced toward each other in the vertical direction (thedirection in which the two rows of fibers have been vertically stacked).As appreciated by comparing FIGS. 4A and 4B, tapering of the opticalfibers 202 occurs after the top row has been at least partially offsetfrom the bottom row. In this manner, collisions (and thus damage)between the top row and bottom row fibers is avoided.

FIG. 5A depicts a top-down view of the two-row ferrule 100 and theinterlacing boot 102 shown in FIG. 1 as the optical fibers 202 have beenguided through the channels 204 of the interlacing boot 102. FIG. 5Bdepicts a cross-sectional view of the two-row ferrule 100 and theinterlacing boot 102 shown in FIG. 1 as the optical fibers 202 have beenguided through the channels 204 of the interlacing boot 102.

As shown in FIG. 5A, the interlacing boot 102 has been sufficientlyinserted over the optical fibers 202 such that end portions of theoptical fibers 202 exit the interlacing boot 102. At this point, theoptical fibers 202 have been offset and interleaved into a single row offibers (a 1D array of fibers). In some embodiments of the invention, thelength at which each of the end portions of the optical fibers 202extend from the interlacing boot 102 varies (due to differences in fiberlength, pathing through the guiding structure 206, etc.).

FIG. 6A depicts a top-down view of the two-row ferrule 100 and theinterlacing boot 102 shown in FIG. 1 as the interlacing boot 102 hasbeen pushed over the fiber optic ribbons 200 to the base of the two-rowferrule 100. FIG. 6B depicts a cross-sectional view of the two-rowferrule 100 and the interlacing boot 102 shown in FIG. 1 as theinterlacing boot 102 has been pushed over the fiber optic ribbons 200 tothe base of the two-row ferrule 100.

As shown in FIG. 6A, the interlacing boot 102 has been sufficientlyinserted over the optical fibers 202 such that the fiber optic ribbons200 have been completely covered. In some embodiments of the invention,the exposed end portions of the optical fibers 202 are cleaved to ensurethat all fibers have the same exiting tip length (as discussedpreviously, some fibers can have shorter or longer fiber tip endsexisting the interlacing boot 102 due to various factors, such as somefibers being offset while others are not—offset fibers will generallyhave shorter fiber tip ends). The optical fibers 202 can be cleaned andcleaved using any suitable process, such as via a laser or mechanicalcleave. Cleaving is also useful for removing end portions of the opticalfibers 202 that were damaged during the realignment process. In someembodiments of the invention, the interlacing boot 102 is then fixed tothe two-row ferrule 100 to secure the fiber bends. In some embodimentsof the invention, the interlacing boot 102 is glued with adhesive to thetwo-row ferrule 100, although other techniques for bonding theinterlacing boot 102 to the two-row ferrule 100 or to the fiber arraysare within the contemplated scope of the invention. In some embodimentsof the invention, the interlacing boot 102 includes a latch (not shown)for latching onto the two-row ferrule 100. In other embodiments of theinvention, the interlacing boot is secured directly to the multiplefiber arrays (not shown). In this manner, the interlacing boot can beused even in applications that do not have a ferrule.

FIG. 7 depicts a cross-sectional view of the two-row ferrule 100 beinginserted into a temporary interlacing comb 700 according to one or moreembodiments of the invention. As shown in FIG. 7, the guiding structure206 discussed previously herein need not be confined to the interlacingboot 102. In some embodiments of the invention, the guiding structure206 is instead housed within a temporary interlacing comb 700.

The optical fibers 202 are offset and interlaced using the interlacingcomb 700 in a similar manner as previously described with respect to theinterlacing boot 102. For example, the optical fibers 202 can be fedthrough the guiding structure 206 within the interlacing comb 700 tophysically offset and interleave the optical fibers 202.

Advantageously, once the optical fibers 202 are interleaved into asingle row of fibers a boot 702 can be inserted over the optical fibers202 and the interlacing comb 700 can be removed. The boot 702 can thenbe fixed to the two-row ferrule 100 and the optical fibers 202 can becleaved in a similar manner as discussed previously herein with respectto FIGS. 6A and 6B.

Placing the guiding structure 206 within a temporary interlacing comb700 allows for the guiding structure 206 to be reused as many times asneeded. The tradeoff, of course, is the increased cost in forming theinterlacing comb 700 in addition to the boot 702. In short, a temporaryinterlacing boot is well-suited to repeatable applications, such asfiber runs having many ferrules of the same pitch (so that the sameguiding structure 206 will work for each ferrule).

FIG. 8 depicts a flow diagram 800 illustrating a method for interleavingan array of optical fibers in a ferrule according to one or moreembodiments of the invention. As shown at block 802, the optical fibersare inserted into a first end of an interlacing boot. In someembodiments of the invention, the optical fibers include a first row offibers and a second row of fibers.

In some embodiments of the invention, the interlacing boot includes abody having the first end adapted for insertion over a ferrule ribbonand a second end opposite the first end. The second end can include anopening. In some embodiments of the invention, the body is taperedbetween the first end and the second end in a first direction.

In some embodiments of the invention, a guiding structure is disposedwithin the body. The guiding structure can include one or more channelsand each channel can be adapted to receive a single optical fiber. Insome embodiments of the invention, each channel includes a first end anda second end and the second end is offset with respect to the first endin a second direction orthogonal to the first direction.

In some embodiments of the invention, the guiding structure is adaptedto receive optical fibers from only a first row of a two-row ferrule. Insome embodiments of the invention, the guiding structure is adapted suchthat a second row of the two-row ferrule bypasses the guiding structure.In some embodiments of the invention, the guiding structure is adaptedto receive optical fibers from both rows of a two-row ferrule. In someembodiments of the invention, the guiding structure comprises one ormore top channels and one or more bottom channels. In some embodimentsof the invention, the guiding structure is adapted to ensure that themaximum fiber bend during offsetting is within allowable fiber bendradii for the given application. In some embodiments of the invention,the allowable fiber bend radii is predetermined based on a givenapplication or fiber type.

In some embodiments of the invention, each channel in the guidingstructure includes a first portion and a second portion. In someembodiments of the invention, the offset of each channel occurs withinthe first portion but not the second portion. In some embodiments of theinvention, the offset of each channel occurs within the first portionand the second portion. In some embodiments of the invention, a majorityof the offset of each channel occurs within the first portion (with aminority of the total offset occurring in the second portion).

In some embodiments of the invention, each channel is tapered. In someembodiments of the invention, tapering of each channel occurs within thesecond portion but not the first portion.

At block 804, the interlacing boot is pushed towards the ferrule to feedthe optical fibers through the guiding structure. In some embodiments ofthe invention, the first row of fibers are physically offset from andinterlaced with the second row of fibers by the guiding structure.Advantageously, even if the offsetting is not perfect initially (withregards to tolerance and the incoming pitch variation of the fiberarray), the very nature of cylindrical fibers means that each fiber willinteract by contact when they are tapered to complete the interleavingoffset.

The method can further include coupling the interlacing boot to theferrule. In some embodiments of the invention, the interlacing boot isglued to the ferrule using an adhesive. In some embodiments of theinvention, the interlacing boot is latched onto the ferrule using alatch built into the interlacing boot or into the ferrule. In someembodiments of the invention, the optical fibers are cleaned and cleavedafter feeding the optical fibers through the guiding structure (asotherwise they may protrude from the interlacing boot at differentdistances).

In some embodiments of the invention, a fiber tip from one or moreoptical fibers is cleaved. In some embodiments of the invention,cleaving the fiber tip(s) includes a laser or mechanical cleave. In someembodiments of the invention, the one or more optical fibers are cleavedsuch that each of the one or more optical fibers protrude a same lengthfrom the interlacing boot.

FIG. 9 depicts a flow diagram 900 illustrating a method for interleavingan array of optical fibers in a ferrule according to one or moreembodiments of the invention. As shown at block 902, the optical fibersare fed into an interlacing comb in a first direction. In someembodiments of the invention, the optical fibers include a first row offibers and a second row of fibers.

In some embodiments of the invention, the interlacing comb includes aguiding structure. In some embodiments of the invention, the guidingstructure includes one or more channels and each channel is adapted toreceive a single optical fiber. In some embodiments of the invention,each channel includes a first end and a second end and the second end isoffset with respect to the first end in a second direction orthogonal tothe first direction.

At block 904, the optical fibers are moved (guided) through theinterlacing comb to force the optical fibers through the guidingstructure. In some embodiments of the invention, the first row of fibersis physically offset from and interlaced with the second row of fibersby the guiding structure. The optical fibers can be guiding through theguiding structure by physically moving the fibers into the interlacingcomb, by moving the interlacing comb over the fibers, or by acombination of opposed fiber and comb movements. In some embodiments ofthe invention, the interlacing comb is divided into multiple movingportions (not shown), and each can be inserted around the top and bottomrow fiber arrays. The offsetting of the top and bottom row of the fiberarrays can then be performed by moving the various portions tosuccessively displace the fiber array to a given offset and pitch priorto inserting the interlacing boot.

At block 906, the optical fibers are inserted into an interlacing boot.The interlacing boot can include a body having a first end adapted forinsertion over a ferrule ribbon and a second end opposite the first end.The second end can include an opening. In some embodiments of theinvention, the body is tapered between the first end and the second endin a first direction. At block 908, the interlacing comb is removed.

The method can further include moving the interlacing boot over theoptical fibers until contact is made with the ferrule. In this manner,the optical fibers are forced through and out of the interlacing boot.In some embodiments of the invention, the interlacing boot is glued tothe ferrule using an adhesive. In some embodiments of the invention, oneor more optical fibers are cleaved such that each of the optical fibersprotrude a same length from the interlacing boot.

Various embodiments of the present invention are described herein withreference to the related drawings. Alternative embodiments can bedevised without departing from the scope of this invention. Althoughvarious connections and positional relationships (e.g., over, below,adjacent, etc.) are set forth between elements in the followingdescription and in the drawings, persons skilled in the art willrecognize that many of the positional relationships described herein areorientation-independent when the described functionality is maintainedeven though the orientation is changed. These connections and/orpositional relationships, unless specified otherwise, can be direct orindirect, and the present invention is not intended to be limiting inthis respect. Similarly, the term “coupled” and variations thereofdescribes having a communications path between two elements and does notimply a direct connection between the elements with no interveningelements/connections between them. All of these variations areconsidered a part of the specification. Accordingly, a coupling ofentities can refer to either a direct or an indirect coupling, and apositional relationship between entities can be a direct or indirectpositional relationship. As an example of an indirect positionalrelationship, references in the present description to forming layer “A”over layer “B” include situations in which one or more intermediatelayers (e.g., layer “C”) is between layer “A” and layer “B” as long asthe relevant characteristics and functionalities of layer “A” and layer“B” are not substantially changed by the intermediate layer(s).

The following definitions and abbreviations are to be used for theinterpretation of the claims and the specification. As used herein, theterms “comprises,” “comprising,” “includes,” “including,” “has,”“having,” “contains” or “containing,” or any other variation thereof,are intended to cover a non-exclusive inclusion. For example, acomposition, a mixture, process, method, article, or apparatus thatcomprises a list of elements is not necessarily limited to only thoseelements but can include other elements not expressly listed or inherentto such composition, mixture, process, method, article, or apparatus.

Additionally, the term “exemplary” is used herein to mean “serving as anexample, instance or illustration.” Any embodiment or design describedherein as “exemplary” is not necessarily to be construed as preferred oradvantageous over other embodiments or designs. The terms “at least one”and “one or more” are understood to include any integer number greaterthan or equal to one, i.e. one, two, three, four, etc. The terms “aplurality” are understood to include any integer number greater than orequal to two, i.e. two, three, four, five, etc. The term “connection”can include an indirect “connection” and a direct “connection.”

References in the specification to “one embodiment,” “an embodiment,”“an example embodiment,” etc., indicate that the embodiment describedcan include a particular feature, structure, or characteristic, butevery embodiment may or may not include the particular feature,structure, or characteristic. Moreover, such phrases are not necessarilyreferring to the same embodiment. Further, when a particular feature,structure, or characteristic is described in connection with anembodiment, it is submitted that it is within the knowledge of oneskilled in the art to affect such feature, structure, or characteristicin connection with other embodiments whether or not explicitlydescribed.

For purposes of the description hereinafter, the terms “upper,” “lower,”“right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” andderivatives thereof shall relate to the described structures andmethods, as oriented in the drawing figures. The terms “overlying,”“atop,” “on top,” “positioned on” or “positioned atop” mean that a firstelement, such as a first structure, is present on a second element, suchas a second structure, wherein intervening elements such as an interfacestructure can be present between the first element and the secondelement. The term “direct contact” means that a first element, such as afirst structure, and a second element, such as a second structure, areconnected without any intermediary conducting, insulating orsemiconductor layers at the interface of the two elements.

Spatially relative terms, e.g., “beneath,” “below,” “lower,” “above,”“upper,” and the like, are used herein for ease of description todescribe one element or feature's relationship to another element(s) orfeature(s) as illustrated in the figures. It will be understood that thespatially relative terms are intended to encompass differentorientations of the device in use or operation in addition to theorientation depicted in the figures. For example, if the device in thefigures is turned over, elements described as “below” or “beneath” otherelements or features would then be oriented “above” the other elementsor features. Thus, the term “below” can encompass both an orientation ofabove and below. The device can be otherwise oriented (e.g., rotated 90degrees or at other orientations), and the spatially relativedescriptors used herein should be interpreted accordingly.

The terms “about,” “substantially,” “approximately,” and variationsthereof, are intended to include the degree of error associated withmeasurement of the particular quantity based upon the equipmentavailable at the time of filing the application. For example, “about”can include a range of ±8% or 5%, or 2% of a given value.

The flowchart and block diagrams in the Figures illustrate possibleimplementations of fabrication and/or operation methods according tovarious embodiments of the present invention. Variousfunctions/operations of the method are represented in the flow diagramby blocks. In some alternative implementations, the functions noted inthe blocks can occur out of the order noted in the Figures. For example,two blocks shown in succession can, in fact, be executed substantiallyconcurrently, or the blocks can sometimes be executed in the reverseorder, depending upon the functionality involved.

The descriptions of the various embodiments of the present inventionhave been presented for purposes of illustration, but are not intendedto be exhaustive or limited to the embodiments described. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of the describedembodiments. The terminology used herein was chosen to best explain theprinciples of the embodiments, the practical application or technicalimprovement over technologies found in the marketplace, or to enableothers of ordinary skill in the art to understand the embodimentsdescribed herein.

What is claimed is:
 1. An interlacing comb for a multiple fiber array,the interlacing comb comprising: a guiding structure comprising a firstrow of channels and a second row of channels, each channel adapted toreceive a single optical fiber of the multiple fiber array in a firstdirection, each channel having a first end and a second end; wherein thefirst end of each channel of the first row of channels is verticallystacked over the first end of a respective one channel of the second rowof channels; and wherein the second end of each channel of the first rowof channels is offset with respect to the second end of the respectiveone channel of the second row of channels in a second directionorthogonal to the first direction.
 2. The interlacing comb of claim 1,wherein each channel comprises a first portion and a second portion. 3.The interlacing comb of claim 2, wherein the offset of each channeloccurs within the first portion but not the second portion.
 4. Theinterlacing comb of claim 2, wherein the offset of each channel occurswithin the first portion and the second portion.
 5. The interlacing combof claim 2, wherein each channel is tapered between the first end andthe second end of the channels in the first direction.
 6. Theinterlacing comb of claim 5, wherein tapering of each channel occurswithin the second portion but not the first portion.
 7. The interlacingcomb of claim 1, wherein the guiding structure is adapted to receiveoptical fibers at a first pitch and interleave the optical fibers at asecond pitch that is greater than or less than the first pitch.
 8. Theinterlacing comb of claim 7, wherein the guiding structure is adapted tobe removable from the multiple fiber array after interleaving theoptical fibers.
 9. The interlacing comb of claim 1, wherein the multiplefiber array terminates from a multi-row multi-termination (MT) ferrule.10. The interlacing comb of claim 1, wherein the guiding structure isadapted to receive optical fibers from both rows of a two-row ferrule.11. A method for interlacing an array of optical fibers coming out froma multiple row ferrule, the method comprising: inserting the array ofoptical fibers into a first end of an interlacing comb, the array ofoptical fibers comprising a first row of fibers and a second row offibers, the interlacing comb comprising: a guiding structure comprisinga first row of channels and a second row of channels, each channeladapted to receive a single optical fiber of the multiple row ferrule ina first direction, each channel having a first end and a second end,wherein the first end of each channel of the first row of channels isvertically stacked over the first end of a respective one channel of thesecond row of channels, and wherein the second end of each channel ofthe first row of channels is offset with respect to the second end ofthe respective one channel of the second row of channels in a seconddirection orthogonal to the first direction; pushing the interlacingcomb towards the ferrule to feed the optical fibers through the guidingstructure, wherein the first row of fibers are physically offset fromthe second row of fibers by the guiding structure; inserting the arrayof optical fibers into a first end of a cap, the cap comprising a bodyhaving the first end adapted for insertion over the multiple row ferruleand a second end opposite the first end, the second end comprising anopening, the body tapered between the first end and the second end inthe first direction; and removing the interlacing comb afterinterleaving the first row of fibers with the second row of fibers. 12.The method of claim 11 further comprising coupling the cap to themultiple row ferrule.
 13. The method of claim 11, wherein the guidingstructure is configured such that a maximum bending of any fiber withinthe guiding structure is within an allowable fiber bend radii.
 14. Themethod of claim 11 further comprising cleaving a fiber tip from one ormore optical fibers.
 15. The method of claim 14, wherein cleaving thefiber tip comprises a laser or mechanical cleave.
 16. The method ofclaim 15, wherein the one or more optical fibers are cleaved such thateach of the one or more optical fibers protrude a same length from thecap.